Composition and process for reducing the octane requirement and minimizing the octane requirement increase in an internal combustion engine



CGMPQSHION AND PROCESS FOR REDUCENG THE OCTANE REQUIREMENT AND MINE/HZ- TNG THE GCTANE REQUIREMENT INQREASE IN ART INTERNAL OOIVIBUSTIGN ENGINE Application December 29, 1954, Serial No. 478,478

7 Claims. (Cl. 123--1) No Drawing.

The present invention relates to a composition useful both for reducing the octane requirement of an internal combustion engine having combustion chamber deposits and for minimizing octane requirement increase thereafter, and to a method of accomplishing this.

Deposits quickly accumulate in the combustion chambers of internal combustion engines in use. An engine with such deposits requires the use of a gasoline with a higher octane rating than does a clean engine if the engine is not to knock, and the dirty engine is thus said to have a higher octane requirement. The deleterious elfects of such acumulations of deposits are particularly noticeable in engines having a high compression ratio because the margin between the octane number of gasolines on the market and the octane requirement of the engine when clean is narrower than for engines having lower compression ratios.

A number of methods have been proposed heretofore for cleaning the combustion chambers of an internal combustion engine. Introducing a liquid solvent into the carburetor while the engine is running produces great pillows of smoke at the exhaust, but upon taking an engine so treated apart after the operation, it is found that little of the deposits have been removed.

in another method metal objects are inserted into the various cylinders through the spark plug holes, the spark plugs replaced and the engine run. This method of operation has been found entirely impracticable. These objects may cause injury to the engine if jammed between moving parts such as a valve head. The number of particles introduced into each cylinder at one time is either so great as to interfere seriously with the combustion and the movement of the valves and piston, or so small that the spark plug for each cylinder will have to be removed and replaced often during a single cleaning. Many of the particles roll out through the valves before the engine gains suflicient speed to make them effective, thus resulting in a waste of particles and in an accumulation thereof in the exhaust manifold and mufiler.

It is still the standard practice to clean an internal combustion engine by removing the head and grinding the deposits away from the tops of the pistons and valves and the recesses in the cylinder head forming the confining surfaces of the combustion chamber. This method is Xpensive and time-consuming.

In application Serial No. 309,359, filed September 12, 1952, now U. S. Patent No. 2,698,008, issued December 23, 1954, to Everett C. Hughes, there is described a method of reducing the octane demand of an internal combustion engine by removing deposits from the surfaces of the combustion chambers thereof. Into the combustion chambers of such an engine is introduced a plurality of discrete solid particles essentially comprising graphite, and then the engine is run. The method does not require a lifting of the cylinder head, is not injurious to the engine, is iner'pensive and requires little time. Therefore, this method represents a practical solution to the problem of reducing octane requirement.

Closely related to the problem of reducing the octane requirement of a dirty engine is the problem of minimizing any increase in the octane requirement of the engine once it has been cleaned.

To minimize the octane requirement increase of an internal combustion engine chemical agents are introduced into the combustion chambers. Such compounds can be incorporated in the fuel or in the lubricating oil on which the engine is operated or by disassembling the engine and coating the surfaces of the combustion zone therewith. While the manner in which such agents function is not fully understood, it is generally agreed that their action is a chemical one.

From the preceding description, it can be seen that the problem of reducing octane demand has been solved by an essentially mechanical method which comprises the introduction of graphite particles into the combustion chambers of an engine and that the somewhat analogous problem of minimizing octane requirement increase has been solved by essentially chemical methods. The present invention combines these mechanical and chemical methods by providing a composition which can be introduced into an internal combustion engine to both reduce octane requirement and minimize octane requirement increase in one simple and convenient operation.

in accordance With the invention, discrete, solid macroparticles consisting essentially of graphite are provided, impregnated with any one or a combination of several chemical agents efiective to minimize octane requirement increase. The impregnated graphite particles are introduced into the combustion chamber of an internal combustion engine and the engine operated. The particles of graphite mechanically remove the deposits on the surfaces enclosing the combustion zone on the engine and simultaneously the surfaces are coated with the chemical agent, whereby subsequent octane requirement increase is minimized.

It is possible to utilize as impregnants for the graphite macroparticles chemical agents which are not capable of being introduced as a component of the fuel or lubricating oil because of lack of compatibility therewith or some other reason. More efiicient contact between the chemical impregnants and the surfaces of the combustion zone is achieved, to obtain optimum minimization of octane requirement increase.

The graphite macroparticles are available from several sources. The particles may comprise either natural or synthetic graphite, and are not required to be of any particular size, shape or hardness. In general, however, the particles should be sufficiently small to permit their passage through the venturi throat of an average carburetor, and for this reason it is recommended that the particles not have a maximum diameter or dimension greater than about inch. The particles may have any desired shape, for example, cubes, cylinders, ellipsoids, or spheres. Cylinders are particularly effective and suitable, and graphite particles are readily available in this form. Preferred are graphite cylinders having a diam- V a V-notch block to prevent slippage.

3 eter of about /s inch and lengths ranging from about /s inch to about inch.

The hardness of the particles is likewise not a critical feature. The particles should be soft enough to be crushed in case any particles should be jammedbetween moving metal surfaces, Without damage to the metal. The harder the particles the more effective they are in cleaning the engine. Preferred particles have a compressive strength of over 10,000 p. s. i., a Rockwell hardness of at least about 110, and a shatter height of at least 35 cm., utilizing a 1.5 ounce weight dropped on the particles.

The particles may consist entirely or primarily of graphite. They may, and desirably do, contain in addition to the graphite such binders as coal tar pitch, synthetic resins, clay, and the like. One type of particle that has been found entirely suitable is prepared by.heat-.

ing petroleum coke to drive otf volatile matter, grinding it to a powder form, mixing it with suflicient coal tar pitch to make the composition plastic enough for extrusion, extruding the coke and graphitizing it in a furnace at high temperatures of the order of 1000 to 2500 C.

All of the above described types of graphite particles are porous to a degree ranging from about 1 to 50% and thus are capable of adsorbing liquids. The chemical agents are therefore adsorbed therein by immersing the graphite particles in the liquid, which can be the pure impregnant, if a liquid, or a solution or dispersion thereof, the concentration depending on the amounts to be incorporated in the particles and the viscosity of the solu- I .tion or dispersion. The resulting particles are then dried if necessary to eliminate the solvent.

It is generally preferred that the impregnated particles comprise from about 1 to about 50% by weight of the agent effective to minimize octane requirement increase.

The chemical agent with which the graphite particles are impregnated can be any of those described in the art. It may thus be a dialkyl sulfite of the general formula, RzSOa, wherein R is a lower alkyl radical preferably containing from about 1 to about 4 carbon atoms as disclosed in application Serial No. 401,038, filed December 29, 1953, by Samuel M. Darling, an inorganic boron compound selected from the group consisting of silver borate and copper borate, disclosed in application Serial No. 417,516, filed March 19, 1954, now U. S. Patent No. 2,725,857, issued December 6, 1955, by Everett C. Hughes and John D. Bartleson, complex reaction products of boron tn'fluoride and an organic oxygen com- 7 pound, disclosed in copending application Serial No.

332,567, filed January '21', 1953, now U. S. Patent No.

2,751,285, issued June 19, 1956, by John D. Bartleson,

of which particularly useful complexes are the boron trifluoride etherates, particularly combinations of boron trifluoride with methyl or ethyl ether, boric' acid, disclosed in application Serial No. 313,788, filed October 8, .1952, by Everett C, Hughes and John D. Bartleson, inorganic boron compounds selected from the groupconsisting of borates, borides and borines of the alkali and alkaline earth metals, disclosed in application Serial No.

403,436, filed January 11, 1954, now U. S. Patent No. 2,725,856, issued December'6, 1955, typical examples of which are sodium perborate, sodium metaborate, sodium tetraborate, potassium metaborate, potassium tetraborate, potassium pentaborate, potassium'perborate, potassium diborine, potassium 'dihydroxydiborine, potasslum p entaborine, lithium metaborate, lithium tetraborate, calcium metaborate, calcium tetraborate, calcium boride, barium boride, strontium tetraborate, and stron- 1 Measured in a Rockwell hardness tester employing a kg. load (total load including internal load on machine) and a 5 inch steel ball and following standard hardness test procedures. Hardness was measured on the curved surface, using by Everett C. Hughes and Milton H. Campbell, includ- 7 ing the alkyl and aryl borates of the formula B(OR)3, the alkyl and aryl borines of the formula BRa, triborine triamine and alkyl derivatives thereof, alkyl and aryl boronic oxides of the formula and mixed alkyl and/ or aryl boryl halides of the formula RBXz, RzBX wherein R of the above formulas represents alkyl or aryl and X represents halogen, of which specific examples are triethyl' borate, triisobutyl borate, triisopropyl carbinyl borate, tritertiary butyl borine, triamyl borine, tributyl borine, and the like, alkyl boronic acids having an alkyl radical of from 6 to 8 carbon atoms of which typical examples are n-hexyl boronic acid and noctyl boronic acid, and esters of alkanediols of 2 to 8 carbon atoms and an alkylboronic acid of 4 to 10 carbon atoms, of which specific examples are the ethylene glycol, propylene glycol, hexanediol, and similar esters of nhexyl boronic acid and n-octyl boronic acid, disclosed in applications Serial Nos. 430,436 and 430,437 filed May of this class include those disclosed in U. S. Patent No.

in aqueous solution "such as ammonium sulfite also can be used.

These compounds may be applied to the particles in 1 the form of a solution or dispersion in a volatile inert.

liquid such as water, hydrocarbons such as gasoline, or lower alkanols, such as methyl and ethyl alcohols.

In order to further illustrate the invention, the ingexamples are presented.

EXAMPLES TO 6 Graphite pellets Were prepared by heating petroleum coke to drive off volatile matter, grinding the residue to powder form and mixing it with suflicient coal tar pitch to make thematen'al plastic enough for extrusion, extruding the coke, graphitizing the. material in a furnace at 2000 to 3000 F., and then converting the mass into pellets.

A quantity of the resulting pellets was placed in a flask and the flask evacuated. A solution of the chemical f agent to be introduced by impregnation was added to the flask without breaking the vacuum in an amount to cover I the pellets. The vacuum was released by openingthe flask to air, after which the free liquid was decanted and the pelletssucked dry on a Buchner funnel and weighed. The following results were obtained.

follow- 7 Adsorption on graphite pellets The above particles can be introduced into an internal combustion engine on each side of the butterfly valve in the throat of the carburetor, after which the engine is run under normal conditions. No further action need be taken, the material removed by the action of the pellets being discharged by the engine through the normal channels.

It is obvious that many changes and modifications in the invention may be made by a person skilled in the art and, accordingly, it is intended that the invention be limited only by the scope of the appended claims.

We claim:

1. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and an agent eiiective to minimiz octane requirement increase into the combustion zone of an internal combustion engine and running the engine.

2. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and a boron compound efiective to minimize octane requirement increase into the combustion zone or an internal combustion engine and running the engine.

3. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macropaiticles consisting essentially of graphite and an ester of an alkanediol of 2 to 8 carbon atoms and an alkyl boronic acid of 4 to 10 carbon atoms efiective to minimize octane requirement increase into the combustion zone of an internal combustion engine and running the engine.

-4. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and an agent selected from the group consisting of copper and silver borate into the combustion zone of an internal combustion engine and running the engine.

5. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and a dialkyl sulfite efifective to minimize octane requirement increase into the combustion zone of an internal combustion engine and running the engine.

6. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and an organic silicone compound effective to minimize octane requirement increase into the combustion zone of an internal combustion engine and running the engine.

7. A process for reducing the octane requirement of an internal combustion engine having deposits in the combustion chambers and for minimizing subsequent octane requirement increase which comprises introducing a composition comprising discrete macroparticles consisting essentially of graphite and a metallic naphthenate effective to minimize octane requirement increase into the combustion zone of an internal combustion engine and running the engine.

References Cited in the file of this patent UNITED STATES PATENTS 1,877,668 Kidder Sept. 13, 1932 2,176,879 Bartell Oct. 24, 1939 2,529,496 Hughes Nov. 14, 1950 2,698,008 Hughes Dec. 28, 1954 2,710,252 Darling June 7, 1955 OTHER REFERENCES Industrial and Engineering Chemistry, vol. 43, No. 12, pp. 2842 and 2843. 

1. A PROCESS FOR REDUCING THE OCTANE REQUIREMENT OF AN INTERNAL COMBUSTION ENGINE HAVING DEPOSITS IN THE COMBUSTION CHAMBERS AND FOR MINIMIZING SUBSEQUENT OCTANE REQUIREMENT INCREASE WHICH COMPRISES INTRODUCING A COMPOSITION COMPRISING DISCRETE MACROPARTICLES CONSISTING ESSENTIALLY OF GRAPHITE AND AN AGENT EFFECTIVE TO MINIMIZE OCTANE REQUIREMENT INCREASE INTO THE COMBUSTION ZONE OF AN INTERNAL COMBUSTION ENGINE AND RUNNING THE ENGINE. 